In Fig. REF  the prediction for the azimuthal correlations \(\Delta \phi _{\rm {Z} \text{j}}\)  for \(\rm {Z} +\) jet production in the back-to-back region is shown.\(\endcsname \)Predictions for the region of small \(\Delta \phi \)  require including the contribution of
higher parton multiplicities, e.g. via multi-jet merging [1]}.

We also show, for comparison, the prediction of azimuthal correlations \(\Delta \phi _{12}\)  for multijet production in the same kinematic region, compared to the measurement of dijet production obtained by CMS [2]}.
We observe that the distribution of azimuthal angle \(\Delta \phi _{\rm {Z} \text{j}}\)  in \(\rm {Z} +\) jet-production for \(p_{\rm T}^{\text{leading}} >200\)   is more strongly correlated towards \(\pi \)  than the distribution of angle \(\Delta \phi _{12}\)  in multijet production. This difference is reduced for \(p_{\rm T}^{\text{leading}} > 1000\)  .
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